Better Networking

What is the main purpose of DHCP (Dynamic Host Configuration Protocol)

To automatically assign IP addresses and other network configuration to client devices on a network.

What are the four steps of the DHCP process (DORA)

Discover, Offer, Request, Acknowledge.

What happens during the DHCP Discover step?

The client sends a broadcast message to find available DHCP servers.

What happens during the DHCP Offer step?

The DHCP server responds with an available IP address and configuration options.

What happens during the DHCP Request step?

The client requests the offered IP address from one of the responding DHCP servers.

What happens during the DHCP Acknowledge step?

The server confirms the IP assignment and finalizes the lease.

What is a DHCP lease?

A temporary assignment of an IP address to a client, valid for a specified period of time.

How does DHCP support PXE Boot?

DHCP assigns an IP and tells the PXE client where to find the bootloader (usually via a TFTP server).

What is NFS used for?

Sharing files over a network as if they were local folders.

What is iSCSI used for?

Accessing remote block storage over a network like a local hard disk.

What are Puppet and Ansible used for?

Automating configuration management and provisioning across multiple servers.

What do Puppet and Ansible do?

Configuration management tool that automates server setup.

What does top do?

Shows real-time system processes, CPU/memory usage, and load average.

What’s the difference between df and du?

• df: Disk free space by filesystem.

• du: Disk usage of files/directories.

When would you use ping vs traceroute?

• ping: Tests basic network connectivity to a host.

• traceroute: Shows the path packets take to a destination.

What does netstat show?

Active network connections, listening ports, and routing tables.

What are the main resources monitored for server capacity?

CPU, memory (RAM), disk storage, and network bandwidth.

What does high CPU usage indicate?

The server is under heavy computational load — may need more CPU cores or process optimization.

What tools can you use to monitor memory usage?

top, free, or vmstat on Linux; Cloud tools like CloudWatch.

What’s the difference between disk capacity and IOPS?

• Capacity = total storage available.

• IOPS = how fast the disk can handle input/output operations.

What’s the purpose of capacity planning?

To anticipate future resource needs and prevent outages, slowdowns, or overprovisioning.

How do you back up a MySQL database?

Use mysqldump:

How do you back up a PostgreSQL database?

Use pg_dump

What is the difference between full, incremental, and differential backups?

• Full: Everything

• Incremental: Only changes since last backup (of any type)

• Differential: Changes since last full backup

What is rsync used for?

To sync directories/files, often over SSH, and supports incremental backups

What does ping do?

Tests connectivity to a host by sending ICMP echo requests and measuring response time.

What does traceroute show?

Shows the path packets take from your machine to a destination, revealing network hops.

What does dig do?

Performs DNS lookups to retrieve A, CNAME, MX, etc. records.

What is curl used for?

Sends HTTP requests from the terminal, useful for testing APIs or web server responses.

What is ServiceNow Asset Management?

A tool for tracking and managing IT assets throughout their lifecycle, from procurement to disposal.

What types of assets can ServiceNow track?

Hardware, software, virtual machines, cloud resources, and non-IT assets.